The US 20020153492 A1 discloses a radiation detector in which photodiode arrays (PDAs) and scintillator crystals are attached to a planar substrate that extends into a volume lateral of the scintillator crystals. Furthermore, connectors are attached to the substrates in said lateral volume, and a plurality of the resulting components are combined to a stack, wherein the volume lateral of the scintillator crystals is filled with epoxy resin.